Tag: e-cigarettes

Electronic cigarettes could be a boon to public health or a major liability, depending on whether they help Americans quit smoking or encourage more young people to try traditional cigarettes, a new report concludes.

The report issued Tuesday wrestles with the potential benefits and harms of the vapor-emitting devices which have been sold in the U.S. for more than a decade. But those effects may not be known for decades, in part, because of how slowly illnesses caused by smoking emerge.

“In some circumstances, such as their use by non-smoking adolescents and young adults, their adverse effects clearly warrant concern,” said David Eaton, of the University of Washington, who headed the National Academies of Sciences, Engineering and Medicine committee that studied the issue. “In other cases, such as when adult smokers use them to quit smoking, they offer an opportunity to reduce smoking-related illness.”

There are no long-term studies on the health consequences of e-cigarettes and little consensus on whether they are effective in helping smokers quit, according to the report requested by the Food and Drug Administration.

The experts found “substantial” evidence that young people who use e-cigarettes are more likely to try cigarettes. On the other hand, experts found only “limited evidence” that cigarettes are effective tools to help adult smokers quit.

The committee’s review of more than 800 studies yielded many findings that were largely in line with prior assessments by other researchers. For instance, the panel found “conclusive evidence” that most e-cigarettes contain numerous chemicals that can be toxic. However, there was equally strong evidence that e-cigarettes contain fewer toxicants and at lower levels than regular cigarettes.

E-cigarettes have been sold in the U.S. since at least 2007. Most devices heat a liquid nicotine solution into vapor and have been promoted to smokers as a less dangerous alternative since they don’t have all the chemicals, tar or smoke of regular cigarettes. E-cigarettes and similar vaping devices have grown into a $4 billion-dollar U.S. industry with thousands of varieties of flavors and customizable products available in specialty shops and online.

The FDA gained authority to regulate the devices in 2016 after years of pushback from the industry. But last year the agency said it would delay the deadline for manufacturers to submit their devices for review until 2022. The decision was blasted by anti-smoking advocates who say some e-cigarette manufacturers target kids with candy and fruit flavors.

The FDA has signaled its intention to begin pushing U.S. consumers away from traditional cigarettes toward alternative products, such as e-cigarettes. The regulatory delay was intended, in part, to give companies more time to research their products.

FDA Commissioner Scott Gottlieb called the link between e-cigarette use and trying smoking in young people “troubling.”

“We need to put novel products like e-cigarettes through an appropriate series of regulatory gates to fully evaluate their risks and maximize their potential benefits,” he said in a statement.

Some other key takeaways and questions from the report:

— Chemicals in e-cigarette vapor, such as formaldehyde, are capable of damaging DNA in humans. However, it’s unclear if the chemicals exist at levels high enough to cause cancer.

The safety of electronic cigarettes is a widely debated issue. The latest research demonstrates that in people who do not smoke, they can alter heart rate variability, which is an indicator of increased adrenaline levels.

Introduced in 2007, electronic cigarettes (e-cigarettes) are now “the fastest-rising tobacco product in the United States.”

There is little doubt that these devices deliver fewer carcinogens to the user, but, because they often contain nicotine, conversations regarding their safety are ongoing.

On the one hand, e-cigarettes offer a relatively safe option for nicotine-addicted individuals. On the other hand, they are seen by some as a new route to addiction with health concerns of their own.

Research published this week in the Journal of the American Heart Association investigates the potential heart health implications of non-smokers using nicotine-based e-cigarettes.

Lead study author Dr. Holly Middlekauff, of the University of California, Los Angeles, says, “While e-cigarettes typically deliver fewer carcinogens than are found in the tar of tobacco cigarette smoke, they also usually deliver nicotine.”

“Many believe that the tar – not the nicotine – is what leads to increased cancer and heart attackrisks. So, we asked the question, are e-cigarettes safe?”

E-cigarettes and the sympathetic response

Nicotine is not a carcinogen, but it is still a drug. It is a sympathomimetic, which is a compound that mimics the sympathetic nervous system, increasing adreline levels in circulation and raising heart rate and blood pressure. These are physiological changes associated with the “fight or flight” response.

It is this activation of the sympathetic nervous system and the influx of adrenaline that worries some medical researchers. These types of actions are, over the long-term, linked with increased cardiovascular risk.

Cardiac sympathetic nerve activity can be measured noninvasively using a heart monitor to detect heart rate variability (HRV), which is the variability in the duration between heartbeats. This measure can be used as a predictor of cardiovascular disease; lower HRV increases risk.

This rise in cardiac sympathetic nerve activity and its associated rise in circulating adrenaline, combined with a lack of long-term data on e-cigarettes, creates concern as to their overall safety.

In other research, Dr. Middlekauff’s team showed that chronic e-cigarette use contributed to increased resting cardiac sympathetic nerve activity.

The current study was designed to find out whether this effect could be seen in acute, or short-term, use of e-cigarettes, and whether it is due to nicotine or other ingredients present in the devices – such as propylene glycol and vegetable glycerin.

E-cigarettes, nicotine, and cardiac risk

In total, 33 healthy volunteers – none of whom smoke cigarettes or e-cigarettes – were involved in the study. Each participant, on separate days, smoked an e-cigarette with nicotine, one without nicotine, and a sham (empty) e-cigarette.

According to the study authors, this is the first study of its kind to separate the nicotine from the non-nicotine components of e-cigarettes in this way.

For each individual, HRV was measured. A blood sample was also taken to assess oxidative stressby measuring levels of an enzyme called plasma paraoxonase.

After analysis, the team found that HRV was significantly altered when individuals used the nicotine e-cigarette but not in the non-nicotine and sham conditions. However, they saw no significant differences in markers of oxidative stress.

Dr. Middlekauff explains how the findings add to the body of evidence against nicotine as a safe drug. “While it’s reassuring that the non-nicotine components do not have an obvious effect on adrenaline levels to the heart,” she says, “these findings challenge the concept that inhaled nicotine is benign or safe.”

She says, “Our study showed that acute electronic cigarette use with nicotine increases cardiac adrenaline levels. And, it’s in the same pattern that is associated with increased cardiac risk in patients who have known cardiac disease, and even in patients without known cardiac disease.”

Limitations and future research

The study has limitations; it included only a small number of participants and studied just one of the thousands of e-cigarette fluids. For this reason, the authors are keen to extend their findings.

“I think that just seeing this pattern at all is very concerning and it would hopefully discourage non-smokers from taking up electronic cigarettes.”

Dr. Holly Middlekauff

In the future, the researchers plan to continue their studies – the team would like to investigate this effect in habitual e-cigarette smokers and take a more in-depth look at the potential role of oxidative stress.

The current findings are likely to intensify an already intense debate. The take-home message is that e-cigarettes are less likely to cause cancer, but they are not without their own dangers.